Tools for inspecting, modifying and rebuilding Elektron Digitone firmware — the Digitone II (DN2) and the original Digitone / Digitone Keys (DN1) — and a set of mods for the Digitone II built with them.

This repository holds code and documentation only. It contains no Elektron firmware, original or modified, and never will. Bring your own OS file — the one Elektron publish for your instrument. Every mod applies to your copy of it, and checks that copy is the one it was measured against before it writes.

Applied with dnfw mods apply, or in the browser on the project site, https://angellinares.github.io/dn2_firmware_explore/, which runs entirely in your browser, with nothing uploaded. The browser and the command line produce the same file, byte for byte; that is tested.

Combining them. dnfw mods matrix tries every pair in both orders and writes the result into docs/mods-compatibility.md and the site. Most pairs combine freely; a few need an order (dnfw mods apply applies them in it), and lfo4, lfowaves and bootscreen exclude each other because each needs the start-up hook. One pair has been flashed together and confirmed on the instrument: bootscreen + layermidi (2026-10-02, docs/flashing.md).

Old projects that halt on load: a project with a damaged song row count halts even stock 1.11 on load (EXCEPTION DS0059). The songguard mod bounds the count, and it is confirmed on the instrument (docs/old-project-load.md).

In development: Waverider, a wavetable machine for the Digitone II modelled on Tonverk's Wavefinder (docs/waverider-feasibility.md). A baked table has been read back on the instrument (Milestone 0), and Milestones 1–4 run offline in digikit's SHARC emulator: our own SHARC reader, inside a real DN2 voice, through the per-track chain, with its tables baked into the DSP image. The first flashable build is Milestone 5.

Python 3.11+, no dependencies.

pip install -e .
dnfw inspect 00_Resources/00_Firmware/Digitone_II_OS1.11_dist.zip
dnfw mods apply Digitone_II_OS1.11.syx --mod lfo4 -o modded.syx

Or without installing: PYTHONPATH=src python -m dnfw.cli.main ...

A .zip as Elektron ship it is accepted anywhere a .syx is.

build, patch apply and mods apply re-load and re-verify their own output before writing it. Nothing leaves this tool that it cannot check.

• Integrity: every checksum and the HMAC-SHA256 signature are recomputed and re-verified on the rebuilt file.
• Boot from reset in an emulator: scripts/emu_boot_check.py, on digikit's ColdFire emulator, against a stock control. A snapshot of a machine that has already booted does not count (docs/emulator.md).
• The engine and save/load: scripts/emu_boot_engine.py runs the audio engine's evaluator and a stored sound through LOAD and SAVE.
• ColdFire encodings: scripts/check_coldfire.py rejects an addressing mode the chip refuses and generic emulators run.
• Per-mod harnesses under scripts/emu_*.py, each with a stock control.
• DSP code runs offline in digikit's SHARC runner and is compared with a Python reference (scripts/sharc_waverider_*.py).
• On the instrument: each hardware test has a written pass and fail in the project's test plan before anything is flashed. The recovery route (stock through the Early Start-up Menu) is proven; send it over a clean MIDI link (docs/flashing.md).

Measured from the images. Evidence in docs/ele3-format.md and docs/mainos-image.md.

• An ELE3 container inside a block-streaming SysEx transport.
• Sections compressed with an aPLib variant. MAIN OS loads at 0x40000400: big-endian ColdFire V4e code, built with GCC and still carrying its C++ RTTI names. Section 7 is the SHARC+ DSP program, as an ADI boot stream.
• The DN2 container is signed with HMAC-SHA256, keyed from material in the image itself, so a modified image can be signed correctly. The DN1 container is unsigned: its trailer is 32 zero bytes.
• The +Drive is a 32 GB eMMC with no filesystem: fixed slots for projects, presets and kits, and about 21 GiB the stock firmware never touches (docs/drive-storage-research.md).

pytest -m "not slow"     # the fast set
pytest                   # everything, a few minutes

Gate F needs an m68k objdump; on Windows, wsl -u root apt-get install -y binutils-m68k-linux-gnu. The browser parity tests need Node. The emulator gates need digikit (docs/emulator.md). Tests that need something absent — the OS images in 00_Resources/, objdump, Node — skip and say so.

GNU AGPL-3.0-or-later. Use it, fork it, change it; keep the notices and pass on the same freedoms. A modified version you distribute — or run as a service — stays open. Same licence as DNX, for the same reasons.

Parts of it derive from MIT projects, whose notices are carried in THIRD-PARTY.md.

The container, transport, codec and integrity work stands on mischa85/elektron-firmware-tool (MIT). The patch model comes from bryantysinger/octa-bt-pt (MIT), and the ColdFire disassembly findings from sambanks/octabam (MIT). The ColdFire and SHARC emulators are m-dwyer/digikit's (GPL-2.0-or-later), used as external tools; our own SHARC code is assembled with js216/selache (GPL-3.0). The Digitone data formats come from the sibling project DNX. What was taken from each, and where this project deliberately diverges, is in docs/references.md.

None of them is affiliated with Elektron, and neither is this. Everything in docs/ was measured from OS files Elektron publish; no Elektron code has been copied into this repository and no firmware is redistributed by it.